Certain custom-built massaging chairs known in the art include a massaging device for performing massaging functions. One type of massaging device is shown in PCT International Application No. PCT/JP99/01340, filed Mar. 17, 1999, by Shimizu Nobuzo. The massaging device used in such chairs includes a track, a massage wheel driving mechanism slidably coupled to the track, and a pair of rotating massage wheels, which are attached to the drive mechanism and translated along the track. The track forms two C-shaped rails. One or more guide wheels having a generally flat circumferential surface are coupled to each side of the driving mechanism. The wheels on each side of the mechanism are fitted within a corresponding rail. Grease is typically applied within the rails to reduce friction between the wheel sides and the rails. The driving mechanism is electrically coupled via electrical wires to a controller that provides the appropriate signal to a motor for driving the mechanism back and forth along the rails. The controller is coupled to a selection device for allowing the user of the massaging chair to turn the motor on and off and to select the speed of the movement of the massaging wheels. The driving mechanism generally includes a limit switch, which controls the motion of the driving mechanism along the rails.
Each massaging wheel is coupled to the driving mechanism about a rotary shaft. The massage wheels are mounted to the rotary shaft eccentrically, and in an oblique fashion relative to the spin axis of the shaft. A second motor rotates the massaging wheels. The wheels are mounted eccentrically and obliquely relative to the spin axis, allowing the outer-peripherals of the massaging wheels to move from side-to-side in a reciprocating fashion. As the driving mechanism travels along the rails, it enables the massaging wheels to translate longitudinally, while the motor causes the wheels to simultaneously move back and forth sideways.
The massaging device is typically located in the back of the chair, with the rails running vertically along the back of the chair and with the massaging wheels making contact with the fabric on the front face of the chair. Thus, the user sitting in the chair comes in indirect contact with the massaging wheels. Typically, the massaging device is centered along the back of the chair so as to straddle the spine of the user. As the driving mechanism rides up and down along the rails, the massaging wheels massage the user's back as they move longitudinally and sideways along the back of the chair.
A problem with existing massaging devices is that with time, wear of the guide wheels causes the guide wheels to rattle within the rails during operation, which may result in an annoying clattering sound. In addition, current massaging devices are often wearing on the chair fabric. As the massaging wheels translate longitudinally along the length of the chair, the wheels' sidewards motion exerts lateral frictional forces on the fibers of the chair's fabric, causing the fibers to tear over time. In a similar fashion, wheel rotation exerts longitudinal forces on the fabric, which also tends to abrade or tear the fabric over a period of time.
Current massaging devices are also hazardous. As the rotating wheels move from side-to-side, the outer-periphery of the wheels rotate in close proximity to the drive motor, creating a pocket whereby objects may be crimped. Because of the compliant characteristics of the chair fabric that is interposed between the user and the massage wheels, the user's limbs or parts of their flesh may be pinched within the pocket, creating a potential hazzard.
Existing massaging devices also do not adequately protect the wiring that sends signals and provides the power to drive the driving mechanism from becoming tangled and chaffed from the movement of the driving mechanism. Tangled and chaffed wires may result in failure of the massaging device and sometimes in hazardous conditions such as the initiation of a fire. Moreover, the driving mechanism limit switches in these devices are openly exposed, leading to the risk of damage or misalignment, either of which may result in subsequent malfunction or damage to the massage mechanism.
Another problem inherent in conventional massaging devices that use grease to induce smooth travel of the guide wheels within the rails, is that the grease can escape the rails and stain the chair. Grease also accumulates dirt and dust, which deteriorates the performance of the massaging device over time. Additionally, current massaging devices are bulky in size and weight. The bulky profile of current massage devices require massage chairs using these devices to grow in size and weight, making it difficult to incorporate the device into chairs having small profiles, such as the bucket seats of cars and aircraft.
Moreover, current messaging devices incorporated within reclining chairs are not modular. When the messaging device requires maintenance, either a technician is required to service the reclining unit at the customer's residence, or the reclining chair, as a unit, must be transported to the service center. Thus, servicing current messaging units can be costly and inconvenient.
What is needed, therefore is a massaging device that preferably does not rattle with age, does not wear away the chair fabric at a considerable rate, and is safe to the user. Such a device preferably provides protection to the wiring between the driving mechanism and the controller against chaffing, provides protection to the driving mechanism limit switches to prevent switch damage or misalignment, and is more compact than current massaging devices. Further, such device is modular, providing convenient and inexpensive maintenance.